The invention relates to the field of hydro-power engineering, namely to hydroelectric power plants and stations, and is primarily intended for conversion of renewable energy possessed by water currents of rivers and other water reservoirs, as well as for conversion of renewable tidal energy into electric power of direct or alternating current.
There is known a hydroelectric power plant including a plate, leanly submerged into water towards the water stream at ⅓ of the depth, with a takeoff of energy of the most potential upper layer of the water stream, elevating the specified layer to a predetermined height, and guiding it to a funnel-shaped mouth of a vertical cavity; and a turbine mounted at the base of the vertical cavity on a vertical axis (see article by A. F. Shirinskiy, New means of adaptation of power systems to natural environments; Journal ‘Hydraulic engineering construction’ NTA Energoprogress—1993, No 11, p. 3).
Such hydroelectric power plants without a dam have a deficiency in that the operation of the turbine depends on the elevation level of the water stream provided by the plate, and consequently the stream potential energy in such a unit is insignificant. Additionally, the turbine is mounted on the vertical axis that results in an increase of overall dimensions of the hydroelectric power plant.
There is also known a free-flow hydraulic unit mounted near a dam and comprising a turbine disposed within its body, joined with an electric generator, (JP Patent No. 58183870, issued 27 Oct. 1983).
The mentioned hydro unit, being installed at the bottom of a river near a dam, allows generating electric energy. However, it has rather low efficiency that is conditioned by the fact that the pressure of water is practically created only by the tilt of riverbed, and therefore the power capacity of such hydroelectric plants is relatively small. In addition, the slow rotation of the driving wheel of turbine requires implementation of heavy and expensive multiplying gears for transmission of the rotation to the electro-generator.
The closest prior art to the present invention in terms of its structure and achievable result is a dam-free hydroelectric power plant comprising a water passage with a cut-off valve and a turbine disposed within the passage (Patent RU No. 2241092).
The design of aforesaid hydroelectric power plant allows utilizing the energy of hydro-impact for increasing the efficiency of the power plant. However, the necessity of raising the water stream above the river level for supplying the stream to the cut-off valve leads to additional losses of the water stream energy that reduces the efficiency of conversion of the stream energy into electric energy. Besides, the necessity of creation of the vertical channel for water delivery to the driving wheel of turbine leads to complication of the design of such power plant, and increasing its dimensions. Additionally, the hydroelectric power plant is efficient only when the water stream flows in one direction.